Abstract
A repeating groundtrack satellite is subject to orbital disturbances caused by repeated passage over the same features on a planet. The terms in the potential leading to critical disturbances can be easily isolated by considering the potential in terms of osculating Kepler elements. As a result of commensurability between the nodal period of the satellite and the rotation of the planet, some specific tesseral harmonics give rise to two kinds of long-period motions which are of different nature. The first and most important of these motions is libration, which is a free oscillation of the ascending node about a stable point on the equator, with an amplitude equal to its initial displacement from the stable point. The second one is dynamic resonance similar to forced mechanical vibration, which, with time, changes the orbital elements. Rates of change due to dynamic resonance were found to be insignificantly small and nonsecular. Calculated libratiori periods and amplitudes and eccentricity changes due to dynamic resonance were verified by a special digital-computer program. Agreement was excellent. Finally, the phasing of satellites in the same orbit was investigated. It was found that, if the orbit librates, very large changes occur in the angular separation of the satellites, but for nonconimensurate orbits, phasing remains stable within 0.1° during several years.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
